Add option to serve Prometheus metrics #671

gristlabs · Oct 12, 2023 · 06559da · 06559da
1 parent 6dfe634
commit 06559da
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Showing 6 changed files with 57 additions and 2 deletions.
diff --git a/README.md b/README.md
@@ -304,6 +304,7 @@ PORT                | port number to listen on for Grist server
 REDIS_URL           | optional redis server for browser sessions and db query caching
 GRIST_SNAPSHOT_TIME_CAP       | optional. Define the caps for tracking buckets. Usage: {"hour": 25, "day": 32, "isoWeek": 12, "month": 96, "year": 1000}
 GRIST_SNAPSHOT_KEEP           | optional. Number of recent snapshots to retain unconditionally for a document, regardless of when they were made
+GRIST_PROMCLIENT_PORT         | optional. If set, serve the Prometheus metrics on the specified port number. ⚠️ Be sure to use a port which is not publicly exposed ⚠️.
 
 #### AI Formula Assistant related variables (all optional):
 

diff --git a/package.json b/package.json
@@ -171,6 +171,7 @@
     "plotly.js-basic-dist": "2.13.2",
     "popper-max-size-modifier": "0.2.0",
     "popweasel": "0.1.18",
+    "prom-client": "14.2.0",
     "qrcode": "1.5.0",
     "randomcolor": "0.5.3",
     "redis": "3.1.1",

diff --git a/sandbox/run.sh b/sandbox/run.sh
@@ -7,4 +7,8 @@ if [[ "$GRIST_SANDBOX_FLAVOR" = "gvisor" ]]; then
   source ./sandbox/gvisor/get_checkpoint_path.sh
 fi
 
-NODE_PATH=_build:_build/stubs:_build/ext node _build/stubs/app/server/server.js
+if [[ -n "$GRIST_PROMCLIENT_PORT" ]]; then
+  require_promclient="--require ./_build/stubs/app/server/prometheus-exporter.js"
+fi
+
+NODE_PATH=_build:_build/stubs:_build/ext node ${require_promclient} _build/stubs/app/server/server.js
diff --git a/sandbox/watch.sh b/sandbox/watch.sh
@@ -15,8 +15,14 @@ if [ ! -e _build ]; then
   buildtools/build.sh
 fi
 
+if [ -n "$GRIST_PROMCLIENT_PORT" ]; then
+  require_promclient="--require ./_build/stubs/app/server/prometheus-exporter.js"
+fi
+
+ls _build/stubs/app/server
+
 tsc --build -w --preserveWatchOutput $PROJECT &
 catw app/client/*.css app/client/*/*.css -o static/bundle.css -v & webpack --config $WEBPACK_CONFIG --mode development --watch &
-NODE_PATH=_build:_build/stubs:_build/ext nodemon ${NODE_INSPECT:+--inspect} --delay 1 -w _build/app/server -w _build/app/common _build/stubs/app/server/server.js &
+NODE_PATH=_build:_build/stubs:_build/ext nodemon ${NODE_INSPECT:+--inspect} --delay 1 -w _build/app/server -w _build/app/common ${require_promclient} _build/stubs/app/server/server.js &
 
 wait
diff --git a/stubs/app/server/prometheus-exporter.ts b/stubs/app/server/prometheus-exporter.ts
@@ -0,0 +1,24 @@
+import { collectDefaultMetrics, register } from 'prom-client';
+import http from 'http';
+
+collectDefaultMetrics();
+
+const server = http.createServer((req: http.IncomingMessage, res: http.ServerResponse) => {
+  register.metrics().then((metrics) => {
+    res.writeHead(200, { 'Content-Type': register.contentType });
+    res.end(metrics);
+  }).catch((e) => {
+    res.writeHead(500);
+    res.end(e.message);
+  });
+});
+
+const port = parseInt(process.env.GRIST_PROMCLIENT_PORT!, 10);
+if (isNaN(port)) {
+  throw new Error(`Invalid port: ${process.env.GRIST_PROMCLIENT_PORT}`);
+}
+server.listen(port, '0.0.0.0');
+
+console.log("---------------------------------------------");
+console.log(`Prometheus exporter listening on port ${port}`);
+console.log("---------------------------------------------");
diff --git a/yarn.lock b/yarn.lock
@@ -1773,6 +1773,11 @@ binary@~0.3.0:
     buffers "~0.1.1"
     chainsaw "~0.1.0"
 
+[email protected]:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/bintrees/-/bintrees-1.0.2.tgz#49f896d6e858a4a499df85c38fb399b9aff840f8"
+  integrity sha512-VOMgTMwjAaUG580SXn3LacVgjurrbMme7ZZNYGSSV7mmtY6QQRh0Eg3pwIcntQ77DErK1L0NxkbetjcoXzVwKw==
+
 bl@^4.0.3:
   version "4.1.0"
   resolved "https://registry.npmjs.org/bl/-/bl-4.1.0.tgz"
@@ -6762,6 +6767,13 @@ process@~0.11.0:
   resolved "https://registry.npmjs.org/process/-/process-0.11.10.tgz"
   integrity sha1-czIwDoQBYb2j5podHZGn1LwW8YI=
 
+[email protected]:
+  version "14.2.0"
+  resolved "https://registry.yarnpkg.com/prom-client/-/prom-client-14.2.0.tgz#ca94504e64156f6506574c25fb1c34df7812cf11"
+  integrity sha512-sF308EhTenb/pDRPakm+WgiN+VdM/T1RaHj1x+MvAuT8UiQP8JmOEbxVqtkbfR4LrvOg5n7ic01kRBDGXjYikA==
+  dependencies:
+    tdigest "^0.1.1"
+
 promise-inflight@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/promise-inflight/-/promise-inflight-1.0.1.tgz#98472870bf228132fcbdd868129bad12c3c029e3"
@@ -7960,6 +7972,13 @@ tcp-port-used@^1.0.1:
     debug "4.3.1"
     is2 "^2.0.6"
 
+tdigest@^0.1.1:
+  version "0.1.2"
+  resolved "https://registry.yarnpkg.com/tdigest/-/tdigest-0.1.2.tgz#96c64bac4ff10746b910b0e23b515794e12faced"
+  integrity sha512-+G0LLgjjo9BZX2MfdvPfH+MKLCrxlXSYec5DaPYP1fe6Iyhf0/fSmJ0bFiZ1F8BT6cGXl2LpltQptzjXKWEkKA==
+  dependencies:
+    bintrees "1.0.2"
+
 term-size@^2.1.0:
   version "2.2.0"
   resolved "https://registry.npmjs.org/term-size/-/term-size-2.2.0.tgz"